Primary open angle glaucoma (POAG) is a significant cause of blindness worldwide. The etiology of POAG is poorly understood and primary prevention is not possible. Current treatments can slow but do not cure this progressive neuropathy. The overall goal of our research is to elucidate the pathogenesis of primary open-angle glaucoma (POAG) making it possible to implement effective screening and prevention strategies and to develop novel therapies. While POAG has a significant heritability, recent genome-wide association studies using moderate sample sizes have only identified a few POAG-related genes with modest effect sizes. These results suggest that large datasets with well-defined phenotypes are needed to fully delineate the genetic architecture of POAG. This proposal will efficiently use existing datasets to create a large sample useful for investigation o genetic determinants of POAG, with a primary focus of identifying genes contributing to the POAG-related quantitative endophenotype, cup-to-disc ratio (CDR). Emerging data suggests that CDR, even when subjectively ascertained, is an important outcome providing valuable insights into the pathogenesis of POAG. Previously we formed two collaborative consortia contributing 3,517 POAG cases and 3,631 controls for GWA studies, the NEIGHBOR consortium (NEI Glaucoma Human genetic collaboration) and the GLAUGEN study (Glaucoma Genetics). The immediate goals of this proposal are: 1) expand the NEIGHBOR and GLAUGEN consortia to create the NEIGHBORHOOD (NEIGHBOR Heritable Overall Operational Database) consortium and database, which will include harmonized genotype and phenotype data for a total of 4,652 POAG cases, 16,909 subjects with CDR and 42,486 controls~ and, 2) use this enhanced dataset to perform meta-analyses to identify novel genes influencing CDR, as well as genes that contribute to POAG. Additionally, this proposal will form the basis of future studies of other POAG related traits and gene-gene and gene-environment interactions for CDR and POAG.